Expansion plug for pipe



Nov. 15, 1949 D. K. STEPHENS EXPANSION PLUG FOR PIPE Filed Feb. 18, 19462 sheets-sheet 1 INVENTOR.

Nov. l5, 1949 D.K. STEPHENS 2,487,991

EXPANSION PLUG FOR PIPE Filed Feb. 18,11946 2 Sheets-Sheet 2 7 /3 ily,4.

A TTO/?NE YS.

yrepairs.

Patented Nov. 15, 1949 EXPANSION PLUG FOR PIPE Dishman K. Stephens,Kansas City, Mo., assignor to Panhandle Eastern Pipe Line Company,Kansas City, Mo., a corporation of Delaware Application February 13,1946, Serial No. 648,286

' 5 claims. (c1. 13s-'90) VThis invention relates to an expansion plugfor pipe, and more particularly to a device for preventing flow of gasin a gas pipe line to the area where a cutting torchis being used onsaid pipe line. k k

y The principal object of the present invention is to provide meansmovable into a gas pipe line for stopping ow of gas in said line.

Pipe lines employed for transmitting fluid, such as natural gas,sometimes become ruptured from various causes. When a rupture occurs avalve near the break is closed to preventfurther flow and loss of gas.It is important that repairs be m'ade immediately to. restore gasservice to the consumers, but the presence of gas in the vicinity of thebreak prevents the use of cutting torches until the gas has been clearedfrom the vicinity. The clearing of the line takes time anddelays Thepresent invention is to safeguard the use of torches and enable theimmediate start of repairs by stopping flow of gas into the vicinity ofthe break and directing the gas remaining in the line tora point remotefrom the torches. Y

Other objects of the present invention are to provide an expansible plugfor a pipe line; to provide an expansion plug of relatively small widthwhich may be inserted in al pipe line at a break therein and moved intothe pipe to a point spaced from the break, then expandedto seal theVpipe, preventing flow of gas to the break; to provide for release of gaspressure in the pipe line to prevent vsaid pressure from forcing theplug out of the line; to provide for escape of the gas remaining in thepipe line during thei use of cutting torches preparatory to furtherrepair of said pipe line;` to provide a resilient member in the plug forexpansion into sealing engage.- m'ent with the pipe; to provide frictionengagement between the plug and the pipe for holding the plug duringexpansion of same; and Vto provide a durable, relatively economical andhighly efficient expansion plug for a pipe line.

In accomplishing these and'other objects of the present invention, Ihave provided improved details o structure, the preferred forms of whichare illustrated in the accompanying drawings wherein:

Fig. 1 is an elevational view of an expansion plug embodying thefeatures of the present in'- vention shown in operative position asapplied to a ruptured pipe line. f Y t n Fig. 2 is a perspective view of'the expansion plug illustrating thearrangement ofthe expansion controlmembers. Y Y

Fig. 3 is a vertical section through the expansion plug particularlyillustrating the relation of the pipe sealing element thereto.

Fig. 4 is an end elevation of the expansion plug.

Fig. 5 is a detailed perspective view of the expansion plug, the partsthereof being shown in spaced relation and partly broken away to betterillustrate their construction.

Referring more in detail to the drawings:

I generally designates an expansion plug constructed in accordance withthe preferred form of the invention for stopping flow of gas in aruptured pipe line or the like. The plug preferably consists of acircular plate 2 having an outside diameter smaller than the insidediameter of Va pipe 3 to which it is adapted to be applied. The plate '2is provided with a central opening 4 through which is extended a.tubular member 5, said tubular member being welded to the inner side ofthe plate as at 6. A ring 1 is sleeved over a portion of the tubularmember extending Yon the outer side of thev plate and welded to thetubular member as at 8 to provide a bearing support for the tubularmember, the periphery of the ring I being welded to the plate 2 as at9.Y The outer side of the plate 2 is also provided with a plurality ofstiffening members In preferably in the shape of T bars, said T barsextending radially from the periphery of the ring I and having theflanges of said bars welded to the Vouter surface of the plate 2. Theportion of the tubular member 5 extending from' the inner surface ofplate 2 is provided with external threads II to threadingly receive acollar I2 as later described.

A ring I3 having substantially the same outside diameter as the plate 2is secured to said plate by means of a lplurality of studs I4 which arefastened to the plate 2 as at I5 and extend through aligning aperturesI6 in the ring I3. The ring I3 'is maintained in spaced relation to theplate 2 by tubular spacers-I1 sleeved over the studs, the plate, spacersand ring I3 being held in a rigid assembly'by nuts I8 threaded on theend of said stud. This arrangement provides a space between the plate 2and the ring I3 adapted to receive a packing ring I9 of resilientmaterial such as rubber or the like, having a normal outer diameterslightly smaller than the pipe in which the plugis to be inserted. Thepacking ringis provided with a plurality of elongated apertures 20adapted to align with the studs It on the plate v2, said apertures 20being of such size asrto pass freely over the spacers I1 to permitradial movement of the packing ring so that it may be extended intoengagement with the inside of a pipe 3. The inner diameter of thepacking ring I5 is slightly larger than the inner diameter of the ringI3 and is adapted to be engaged by a Yplurality of shoes 2I preferablyconsisting of arcuate flanges 22 of such width that they may Dass freelybetween the ring I3 and the plate 2 to engage the packing ring I9. Theshoes 2l are provided with inwardly extending flanges 23 adapted toengage the inner surface of the plate 2 to provide bearing supports forthe shoes 2l. 'I'he shoes 2| are provided with centrally 'arrangedspaced bosses 24 adapted to receive the ends of toggle links 25therebetween. The bosses 24 are provided with apertures 26 aligning withapertures 21 in the toggle links to receive the shanks 28 of bolts 29.The bolts provide a pivotal connection between the toggle links and theshoes, said bolts being held in place by nuts Sil and 3-I. The outerendsofthe toggle linksw25 are provided "with apertures 32 adapted to Ialignwith apertures 3'3 in spaced ears 34 'and 35 on a sleeve S5 having aboreslidable over the tubular member 5. Bolts 38 extend :through 'therespective apertures 32 and 33( to provide pivotal connection Abetweenthe links 25 and the sleeve se, said bolts lleing locked 'in place bynuts 39. The outer end of thersleeve 3'6 is provided with a flange leadapted to be engaged by a flange 4I on the inner end of 'theco'llar I2,whereby threading the collar 'I2 'on 'the tubular member 5 moves thesleeve 3&5 ynsai'd ineinber 5 toward 'the plate 2 and the shoes 2l@upwardly toY expand the resilient packing ring Ts. The cellar 1 2 maybe provided with a tubular extension 42 whlen'may be welded to "saidcollar or 'connected by suitable pipe connections wl'i'e'r'eby the bore453y 'of the tubular member E lcoinin'u'r'iicates with the bore of thetubular eX- 'te'ns'ion 'E2 to 4pr'c'nfitle a duct for 'earryin'g gas toa 'r'einot'e point.

The use of an expansion plug constructed and assembled 'as described,particularly in sealing a ig'as "p'ipe line 3 having ariipture l5"therein, is as fbll'vvs:

, When a pipe is ruptured, Vthevnearest valve thereto controlling1lowthroughthe'line is closed. However, there is suincient gas remainingin 'the -l'in'e 'to `prevent the use 'of cutting torches in the area ofthe rupture. Inorder to stop flow of gas to the ruptured areajoflthepipe an expansion plug I is inserted into the break and expanded untilthe packing Kring I9 `engages the inside of sa-idpipe. The expansionplug Yis Avery narrow and is thereby adapted to be inserted in any typeof break in the pipe, whether the Apipe be flattened or split, as thecollar I2 may be removed yfrom the tubularmernber 5 before insertion of`the plug into said pipe. After the -plug is inserted in the pipe, theextension 4member and `collar -I2 -a-re inserted in the vpipe and thecollar threaded on the tubular member 5, the flange 4I on the collar`I-2 vengaging the flange 4I) o n theA sleeve to force said sleevetoward the plate 2 and the shoes 2| outvwardly against the packing lringI9 by action of the toggle links 25. Thelinks may be held by the opratorto'prevent turning of vthe tubular mem'- ber 5 while the collar I2 isbeing threaded thereon until there i'svsulncientfrictional 4engagementbetween the-packing ring lI 9` and the pipe l3 to hold said 4plugstationary `during continuous threading movement of the `collar I2. -Theplug vmay be then -moved further into the pipe `away vfrom the break 46'and 'after it Ahas been moved 'a sufficient distance, the -extension'42 may 'be :rotated vto turn the collar I2 to further move the sleeve36 toward the plate 2, thereby exerting pressure through the togglelinks 25 and the shoes 2| to force the packing ring into sealingengagement with the interior of the pipe 3. The passage in the tubularmember 5 and extension 42 may be closed, but an increase of pressure inthe pipe line sufficient to force the plug back towards the break insaid line is possible. Therefore, it is preferable that the passage inthe tubular member 5 and extension l2 be open to permit gas to flowtherethrough and prevent a build-up of pressure in the line. In order toconvey the gas away from the vicinity of the break, additional pipefittings 4l are preferably applied to the end of the extension 42, theend o'f the pipe ttings 41 being open to permit escape Ioff the 'gaswhich is ignited t0 prevent any danger therefrom.

Itis obvious the present invention when applied to a ruptured pipe asdescribed will prevent the presence of ga's 'ia-round 'the rupture orbreak in said line and perin-it the ilse of a cutting torch for lsuarngthe ends of the pipe 3 in preparation fr further repairs `on the pipe.When the ends of the pipe are squared and there is no further use 'f'oicutting torches iin that area, the pipe ttings 1H may be removed andtheextension 4'2 rotated to turn the collar I2 n the threaded 'portion IIof the tubular member 5, permitting the 'shoes -'2`I to be retractedfrein the resilient .packing ring 'until such packing 'ring no longer'engages the pipe. The plug may then be removed -frorn the Ipipe line 3and further repairs ymade thereon as fin conventional practice.

What VI fcla'im vand desire to secure by Iletters Patent is:

1. In an 'apparatus of the character described, a gas pipe line having aruptured portion, anexrpansionplug for the pipe -li-n'e including acircular plate, a coaxial tubular shaft 'member extending Vfrom Esaidplate and having screw threads thereon spaced from 'said plate, said'tubular -shaft having 'communication with the rpipe V-line `on theopposite side of said plate, a ring secured to said .plate in spacedIrelation thereto, a resilient member filling the space between theplate vand ring, tubular ineans 'having `one end threadedly engaged withthe fshaft vmember for Vmoving the plug into the line to fa 'point-spaced from the point 'of rupture,

and in'eans movable 'on vthe shaft `'member in vre'- spon's tolrotationof the tubular means and having operative engagement with 4theresilient member for expanding `said resilient member into sealingengagement with the pipe, said tubular pli-lg moving vI'nean's andhaving communication `throughthe tubular shaft with the pipe line for'transmitting rany 'gas "therein to a point remote vfrom `t-he point of"rupture of said .pipe line.

'2. in an apparatus lof the character described,

m -a circular plate, a coaxial tubular shaft Cmember extending from said.plate in .perpendicular relatin thereto, 1a 4ring spaced Ifrom theplate, means securing the ring 4to said pla'te,'a resilient lmember7filling 'the space Abetween the pIaEteiand-ring, shoes engaging theresilientmeinber, means lfmova'ble on the shaft mem'ber, vand -flinks`on said 'movable fmeafns havngconnection with said shoes 'forim'ovingthe resilient member outwardly relatively'of the ring'andaplaite'for'engaging'a pipe to be sealed in response to fmoverrlent ofisaidmovable imeans fon lthe shaft in'ember.

3. In an apparatus of the lcha'ra'cter described, fa `circular plate, 1aceaxiafl Atubular shaf-t "member Aeli-filiriding -IfCllrrSail lplat'efin plperidelar rela'- tion thereto, a ring securedibfsaidplateinfspaeerelation thereto, a resilient member filling the space between the plateand ring, a sleeve movable on the shaft, shoes engaging the resilientmember, links operatively connecting the sleeve with the shoes, andmeans for moving the sleeve on the shaft member for causing the shoes toforce the resilient member outwardly into sealing engagement with a pipeto be sealed,

4. In an apparatus of the character described, a circular plate, acoaxial shaft member extending from said plate in perpendicular relationthereto, said shaft having screw threads thereon in spaced relation tothe plate, a ring secured to said plate in spaced relation thereto, aresilient member lling the space between the plate and ring, a sleeveslidable on the shaft, shoes engaging the resilient member, linksoperatively connecting the sleeve with the shoes, and means threadedlyengaging the threads on the shaft and rotatable thereon for moving thesleeve on the shaft mem-ber in response to said rotation for causing theshoes to force the resilient member outwardly into sealing engagementwith the pipe to be sealed.

5. An expansion plug for sealing a ruptured gas pipe line at a pointremote from the rupture comprising, a circular plate, a coaxial tubularshaft member extending from said plate in perpendicular relation theretoand having communication with the pipe line on the opposite side of saidplate, said tubular shaft having screw threads thereon in spacedrelation to the plate, a ring secured to said plate in spaced relationthereto, a resilient member filling the space between the plate andring, a sleeve slidable on the tubular shaft, shoes engaging theresilient member, links operatively connecting the sleeve with theshoes, and tubular means having one end thereof threadedly engaged withthe shaft for moving the plug into the pipe line to a point spaced fromthe point of rupture, said tubular means having communication throughthe tubular shaft with the pipe line for transmitting any gas therein toa point remote from the point of rupture, said tubular means engagingthe sleeve for moving same on the shaft member in response to rotationof said tubular means for causing the shoes to force the resilientmember outwardly into sealing engagement with the pipe.

DISHMAN K. STEPHENS.

REFERENCES CITED The following references are of record in the le ofthis patent:

UNITED STA'IES PATENTS Number Name Y Date 411,978 Chisholm Oct. 1, 1889'705,059 Flynn July 22, 1902 1,233,214 Frew July 10, 1917

